Building panel and method of making same



' Sept. 7, 1965 D. L. RICHTER 3,204,372

BUILDING PANEL AND METHOD OF MAKING SAME Original Filed Sept. 16, 1960 3 Sheets-Sheet 1 INVENTOR DONALD L. RIC

Sept. 7, 1965 D. RICHTER 3,204,372

BUILDING PANEL AND METHOD OF MAKING SAME Original Filed Sept. 16, 1960 3 Sheets-Sheet 2 INVENTOR DONALD L. RICHTER P 1965 D. 1.. RICHTER 3,204,372

BUILDING PANEL AND METHOD OF MAKING SAME Original Filed Sept. 16, 1960 5 Sheets-Sheet 3 INVENTOR DONALD L. RICHTER f/ BY ATTORNEY United States Patent 3,204,372 BUILDING PANEL AND METHUD 0F MAKING SAME Donald L. Richter, Torrance, Calil., assignor to Kaiser Aluminum & Chemical Corporation, ()akland, Calitl, a corporation of Delaware Continuation of application Ser. No. 56,585, Sept. 16, 1960. This application Mar. 18, 1964, Ser. No. 352,872

11 Claims. (Cl. 5280) This invention relates to structural building units for use in various parts of buildings or shelters such as roofs, floors and walls or combinations thereof. More particularly, it is concerned with providing a novel building unit of compound curvature together with a novel method for manufacturing the same from readily available material.

The instant structural building unit and the method of fabricating the same constitute improvements over those disclosed in my prior Patent 2,891,491 issued June 23, 1959. This application is also a continuation of application Serial No. 56,585, filed September 16, 1960, and now abandoned.

Accordingly, it is among the primary purposes of the instant invention to provide a novel structural building unit of compound curvature together with a simplified method for fabricating the same.

The various aspects, objects and advantages of the present invention will be more fully understood by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a top plan view of a building unit of the instant invention;

FIG. 2 is a perspective view of a typical building or shelter which may be fabricated or built while using the structural units of the instant invention;

FIG. 3 is a sectional view with parts removed taken substantially along the line 3--3 of FIG. 1;

FIG. 4 is a sectional view taken substantially along the line 4-4 of FIG. 1;

FIG. 5 is a sectional view through a typical joint between the building units such as those shown in the building or shelter of FIG. 2;

FIG. 6 is a schematic plan view of one side of a sheet that can be used in the building unit and shows the first step in imparting compound curvature to the sheet;

FIG. 7 is a sectional view taken along the line 77 of FIG. 6;

FIG. 8 is another schematic plan view of the sheet shown in FIG. 6 and discloses a further step in imparting compound curvature to the sheet; and

FIG. 9 is a perspective view of the finally formed building unit with its final compound curvature.

With further reference to the drawings, it will be noted that the structural building unit 2 of the instant invention is one of compound curvature. Although this unit can be fabricated from a single skin or membrane 4 appropriately secured to a quadrilateral frame 5 which is made up of individual frame members 6 and 6', the structural unit can also comprise spaced, similarly shaped and curved membranes between which a suitable insulating material 8 is disposed. Each skin or membrane 4 can be made from a suitable sheet material such as sheet aluminum. The frame members 6 and 6, which will be described in more detail hereinafter, can be advantageously made in the form of aluminum extrusions. Each of the opposing side frame members 6' are approximately straight and parallel as seen in plan although they are not necessarily of equal length. The same applies to the opposing end members 6. All of these frame members are secured together at their ends in such a fashion as 3,204,372 Patented Sept. 7, 1965 to define a skew figure in substantially the same fashion as disclosed in my previous Patent 2,891,491.

The skins or membranes which are secured to one or both sides of the frame members 6 and 6' have hyperbolic and paraboloidal form. That is to say, they have the same general contour or configuration as the building unit of my previous Patent 2,891,491. Thus, the two diagonal corners 10 and 12 are depressed above the original plane of the fiat sheet or fiat frame while the opposing diagonal corners 14 and 16 are displaced below the original plane of the flat sheet or frame. The resultant structural unit 2 is thus roughly curved concavely along the dot-ted line 18 and convexly along the dotted line 20 when viewing the structural unit from above as in FIG. 1.

A novel method will now be described, reference being made to FIGS. 6-9, whereby the individual skins or sheets 4 can be conveniently compoundly curved. The starting material comprises a fiat skin or sheet 4 such as a flat sheet of aluminum. This flat sheet is roughly quadrilateral in configuration and it is provided with substantially straight and parallel sides 23 and 24. The two ends 25 and 26 are somewhat concavely curved or approximately so. The first curvature, such as the curvature generally shown along the line 20 of FIG. 1, is produced by progressively curving the sheet in one plane. As indicated in FIG. 6, this curving of the sheet 4 in one plane is accomplished by placing successive creases in the surface 29 of the flat sheet along the spaced and substantially parallel crease lines 28. These crease lines, it will be noted, also are substantially parallel to opposed side edges 23 and 24 of the flat sheet. These creases are imparted along the successive crease lines 28 until the sheet roughly takes the curvature shown in FIG. 7. As shown in FIG. 6, creases 28 combine with ends 25 and 26 to delineate somewhat rectangular figures on the faces of the sheet.

After the sheet has been curved in one plane, it is then turned over or reversed such that the opposite surface 30 is presented. When the opposite surface 30 has been presented and while the membrane or sheet 4 is in somewhat of a curved condition along one plane, this opposite surface 30 of the sheet is then creased along spaced and substantially parallel crease lines 32. Crease lines 32 extend from one end 25 to the opposing end 26 of the sheet. These crease lines 32 are interposed between and are diagonally and intersectingly disposed with respect to the crease lines 28 on the first-mentioned surface 29 of the sheet. As the diagonal creases 32 are imparted or formed on the surface 30, they also produce a displacement or gathering of the intermediate areas 34 of the sheet which are also immediately adjacent to crease lines 32. This displacement takes place on the opposite surface from surface 30 or on surface 29 preferably in the form of triangularly shaped corrugations 60 which have a uniform configuration and angles of inclination from one end to the other.

In other words, the formulation of the creases 32 causes the sheet to be corrugated along these lines. These corrugated portions or corrugations 60, wherein the crests are at the crease lines 32, have constant angles of inclination on each side. At the same time that these corrugations 60 are imparted to the sheet, the sheet begins to assume a substantially quadrilateral figure of the type shown in FIG. 1 or substantially so. Creases 32 and 28 can both be imparted to the sheet by a conventional brake press. At the same time that the creases 32 are imparted to a sheet, ends 25 and 26 which have been previously curved will tend to straighten out so that in the finished membrane or sheet provided with a compound curvature all four sides will be straight or approximately so. At the same time the areas 36 of the sheet or membrane immediately adjacent the points of intersection of crease lines 32 and 28 will'tend to flatten out. Accordingly, in the finally fabricated sheet that is used in the structural unit, the corrugated portions formed by the creases 32 will have a greater amplitude or height in the part of the areas 34 in the intermediate or center portion of a sheet than at the end edges 26 and 25. In other words, the corrugations 60 almost virtually disappear at the end edges 25 and 26 although across the middle or intermediate portion of the sheet they have a substantial height.

Although the sheet will tend to assume this compound curvature upon being formed in the brake press and at the time that the lines of creases 32 are imparted to it, it may be desirable to obtain an additional skew. This can be done by grasping the two diagonal corners and 12 and twisting them in opposite directions until the final compound curvature is obtained.

The number of creases 32 and 28 which are placed in the sheet will, of course, depend on the ultimate curvature and the size of the finished membrane that is desired. In any event, the method proposed herein provides an extremely convenient and accurate way of producing a compound curvature in a sheet material and in particular a sheet material which is normally not readily deformable in a compound manner such as a sheet of aluminum or other sheet metal. After the sheets have been formed in the manner proposed and after these have been additionally skewed, if desired, they form the final compound curved structure shown in FIG. 9. At that time one or more finally formed sheets 4 are secured to end and side frame elements 6 and 6'.

Although various types of frame members may be used depending upon the results desired, one advantageous embodiment of the invention contemplates that the frame members be made of aluminum extrusions. When made in the form of an extrusion, frame member 6, for ex ample, is provided with flange portions 40 to which the end edges of the panels or membranes 4 are afiixed by means of rivets or bolts 42. Member 6 can also have a concavely curved surface 44 on one side thereof which mates with a correspondingly convexly curved surface 46 on an opposing frame member 6 or 6', as the case may be,

to which one or more skins or sheets 4 have also been secured by means of flanges 40' and bolts 42. When the frame members 6 and/or 6' of the opposing units 2 are secured together by means of bolts 48 thrust through projecting ribs 50 in the two ends of the frame members, a secure joint is formed between adjacent panel units 2. Thereafter, a suitable caulking or sealing material is sprayed or otherwise deposited over the top of the joint to make it substantially waterproof, particularly in the case of where these units 2 are used as part of a roofing structure. Also depending on how the structural units are disposed, an end frame member 6 of one unit may be joined to an end frame member 6 or a side frame member 6' of another unit. It is also obvious, as indicated in FIGS. 3, 4 and 5, that the shapes of the frame members 6 and 6' can be modified depending on the angle at which one building unit 2 is to be disposed with respect to an adjacent building unit 2.

Various types of insulating core materials can be sandwiched in between a pair of panels such as those disclosed in Baroni Patent 2,912,940 issued November 17, 1959. In some instances the materials could be phenolics, vinyl or epoxy plastic materials, etc., and they may be of such a nature that they seal themselves to the skin members 4. The corrugations 60, which may be advantageously made in the form of triangles, progressively decrease in height from the intermediate portion of the sheet toward the outer margins thereof. They facilitate the fabrication and bending of the sheet. In forming the sheet they simulate compound curvatures both structurally and visually whereby they impart a very pleasing appearance to the sheet.

An advantageous embodiment of the invention has been herein disclosed and described. It is obvious that various changes and modifications may be made therein without departing from the spirit and scope thereof as defined by the appended claims wherein What is claimed is:

1. A structural building unit comprised of a flexible sheet having compound curvature and opposedends and sides, said sheet having an undulating surface including a plurality of spaced and parallel crests which are arranged in general parallel relationship to the two opposed sides of the sheet and a plurality of troughs alternating therewith with each trough being disposed between a pair of adjacent crests, each crest having a uniform angle of inclination from one end to the other and the longitudinal axis of one crest in a pair of adjacent crests intersecting with the longitudinal axis of the trough associated there with at one of the opposed ends of the sheet while the longitudinal axis of the other crest in said pair of crests intersects with the longitudinal axis of the said trough at the other opposed end of the sheet.

2. A structural building unit as set forth in claim 1 wherein the crests and troughs of the undulating surface define portions which are substantially triangular in cross section throughout.

3. A structural building unit as set forth in claim 1 wherein said crests and troughs have a maximum amplitude in the central portion of the sheet.

4. A building unit comprised of a flexible sheet having the configuration of a hyperbolic paraboloid and opposed ends and sides, said sheet having an undulating surface including a series of spaced crests which are arranged in general parallel relationship to the two opposed sides of the sheet and to each other and an alternating series of troughs which are arranged parallel to each other as Well as being diagonally disposed with respect to the crests in said series of crests, the longitudinal axis of each trough in said series of troughs being located between the longitudinal axes of the crests of a pair of adjacent crests associated therewith and fully intersecting with the longitudinal axis of one of said crests in said pair of crests adjacent one of the opposed ends of the sheets and with the longitudinal axis of the other of said crests in said pair of crests at the other opposed end of the sheet.

5. A building unit as defined in claim 4 wherein said series of crests are impressed on one surface of the sheet and said series of troughs comprise impre'ssments on the reverse surface of the sheet.

6. A building unit as defined in claim 4 wherein said crests and troughs each have a maximum amplitude in the central portion of the sheet.

7. A structural building unit comprised of a quadrilateral frame having opposed sides and ends; a pair of flexible sheets having compound curvatures disposed in spaced relationship therebetween; each of said sheets being provided with side and end edges secured to the respective'sides and ends of the frame; each of said sheets also having a series of spaced crests which substantially parallel each other and the two opposed sides of the frame, and a plurality of alternating troughs having uniform angles of inclination from one end to the other disposed diagonally of said two opposed sides of the frame with the longitudinal axes of the crests of a pair of said crests fully intersecting the longitudinal axis of the trough associated therewith at each of the opposed ends of the sheet in such a fashion that the longitudinal axis of one of the crests in said pair of crests intersects the longitudinal axis of the trough at one of the opposed ends of the sheet, while the longitudinal axis of the other of said crests in said pair of crests intersects the longitudinal axis of the trough at the other opposed end of the sheet.

'8. A method of imparting compound curvature to a planar and approximately quadrilateral sheet comprising the steps of progressively curving the sheet in one plane by progressively creasing one surface of the sheet along spaced and substantially parallel lines, thereafter progressively curving the sheet in another plane by turning the sheet over and creasing the opposite surface of the sheet along spaced and substantially parallel lines which are interposed between and diagonally disposed with respect to the lines on the first-mentioned surface of the sheet.

9. A method as set forth in claim 8 including the steps of extending the lines of creases on said opposite surface of the sheet until they intersect with the lines of creases on the first-mentioned surface of the sheet.

10. A method as set forth in claim 8 including the step of simultaneously displacing the portions of the sheet immediately adjacent the second-mentioned lines of creases out of the normal plane of the sheet and in a greater amount in the central portion of the sheet than at the periphery thereof during the creasing of the last-mentioned and opposite surface of the sheet.

11. A method of imparting compound curvature to a planar and approximately quadrilateral sheet comprising the steps of progressively curving the sheet in one plane interposed between and diagonally disposed with respect to the lines on the first-mentioned surface of the sheet and during the creasing of the reverse surface of the sheet simultaneously displacing the central areas of the sheet substantially out of the normal plane of the sheet, and thereafter twisting diametrically opposite corners of the sheet in opposite directions so as to impart the final compound curvature to the sheet and during said twisting causing displaced portions of the sheet adjacent the terminal ends of the diagonal creases to flatten out.

References Cited by the Examiner UNITED STATES PATENTS 2,386,018 10/45 Watter 29449 2,857,662 10/ 5 8 Allen 29-449 2,905,113 9/59 Fuller 52 2,912,940 11/59 Baroni 50-52 FOREIGN PATENTS 211,025 9/60 Austria.

HENRY C. SUTHERLAND, Primary Examiner.

JACOB I. NACKENOFF, Examiner. 

1. A STRUCTURAL BUILDING UNIT COMPRISED OF A FLEXIBLE SHEET HAVING COMPOUND CURVATURE AND OPPOSED ENDS AND SIDES, SAID SHEET HAVING AN UNDULATING SURFACE INCLUDING A PLURALITY OF SPACED AND PARALLEL CRESTS WHICH ARE ARRANGED IN GENERAL PARALLEL RELATIONSHIP TO THE TWO OPPOSED SIDES OF THE SHEET AND A PLURALITY OF TROUGHS ALTERNATING THEREWITH WITH EACH TROUGH BEING DISPOSED BETWEEN A PAIR OF ADJACENT CRESTS, EACH CREST HAVING A UNIFORM ANGLE OF INCLINATION FROM ONE END TO THE OTHER AND THE LONGITUDINAL AXIS OF ONE CREST IN A PAIR OF ADJACENT CRESTS INTERSECTING WITH THE LONGITUDINAL AXIS OF THE TROUGH ASSOCIATED THEREWITH AT ONE OF THE OPPOSED ENDS OF THE SHEET WHILE THE LONGITUDINAL AXIS OF THE OTHER CREST IN SAID PAIR OF CRESTS INTERSECTS WITH THE LONGITUDINAL AXIS OF THE SAID TROUGH AT THE OTHER OPPOSED END OF THE SHEET. 